Two Iterative Acceleration Techniques for Short Characteristics Method Applied to Two Dimensional Heterogeneous Cartesian Cells

Two types of acceleration techniques for solving the one group S_N transport equation with the short characteristics method are described. The first scheme involves the synthetic method Boundary Projection Acceleration (BPA), while the second one is inspired from two non-linear diffusion (NLD) techniques, named, the Interface Flux Discontinuity Factor (IFDF) and the Coarse Mesh Finite Difference (CMFD). All presented methods have been implemented on the S_N Cartesian mesh solver of the APOLLO2 lattice code using the method of short characteristic, and applied to the Heterogeneous Cartesian Cell. Numerical results are presented for MOX-UOX assembly calculations as well as for the C5G7-MOX benchmark. (author)